Effect of TiO2–SiO2 on microstructure and mechanical characteristics of zirconium corundum abrasives by sol-gel method

Abstract

Zirconium-toughened-alumina (ZTA) corundum abrasives were successfully fabricated with TiO2–SiO2 co-doping by using the sol-gel method. Single particle compressive strength of the obtained ZTA corundum abrasive was evaluated upon the addition of TiO2–SiO2 in different amounts. The effect of TiO2–SiO2 content on the microstructure of the product was investigated. The X-ray diffraction (XRD) results illustrated that ZrO2 is present in the α-Al2O3 matrix in the form of t-ZrO2. Ti2ZrO6 starts forming when the composition of TiO2–SiO2 is 2 wt% and increases with its addition. The sample doped with 3 wt% TiO2–SiO2 possessed a maximum single particle compressive strength of 45.5 N and a narrow grain size distribution,but excessive TiO2–SiO2 (>3 wt%) causes an abnormal grain growth. The fracture toughness of the composites dramatically increases up to 7.89 Mpa·m1/2 compared to the monolithic. A crack closure was obviously observed in the ZTA abrasives. The influence of the second phase on its mechanical properties was analyzed.